Definitions

• Asthenia: motor impairment without loss of muscle power
  • Motor Impairment Due to Joint Dysfunction
  • Motor Impairment Due to Pain
• Muscle Weakness: motor impairment with loss of muscle power

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Etiology

Unilateral Weakness

• Brain Abscess (see Brain Abscess)
• Brain Tumor
  • Glioblastoma Multiforme (GBM) (see Glioblastoma Multiforme)
  • Glioma (see Glioma)
  • Meningioma (see Meningioma)
• Cerebral Venous Thrombosis (see Cerebral Venous Thrombosis)
• Hemiplegic Migraine (see Migraines)
  • Clinical
    • XXX
• Intracerebral Hemorrhage (Hemorrhagic Cerebrovascular Accident) (see Intracerebral Hemorrhage)
• Ischemic Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident)
  • Internal Carotid Artery Cerebrovascular Accident (CVA)
    • Progressive/Stuttering Onset of Middle Cerebral Artery Syndrome (and Occasionally Anterior Cerebral Artery Syndrome in Cases Where There is Inadequate Collateral Blood Flow)
  • Anterior Cerebral Artery Cerebrovascular Accident (CVA)
    • Abulia
    • Gait Apraxia
    • Grasp/Sucking Reflexes
    • Motor and/or Sensory Deficit: lower extremity > face and upper extremity
    • Paratonic Rigidity
  • Middle Cerebral Artery Cerebrovascular Accident (CVA)
    • Dominant hemisphere: aphasia, motor and sensory deficit (face, arm > leg > foot), may be complete hemiplegia if internal capsule involved, homonymous hemianopia
    • Non-dominant hemisphere: neglect, anosognosia, motor and sensory deficit (face, arm > leg > foot), homonymous hemianopia
  • Posterior Cerebral Artery Cerebrovascular Accident (CVA)
    • Homonymous hemianopia
    • Alexia without agraphia (dominant hemisphere)
    • Visual hallucinations
    • Visual perseverations (calcarine cortex)
    • Sensory loss
    • Choreoathetosis
    • Spontaneous pain (thalamus)
    • Cranial Third Nerve palsy
    • Paresis of vertical eye movement
    • Motor deficit (cerebral peduncle, midbrain)
  • Penetrating Artery Cerebrovascular Accident (CVA)
    • Pure motor hemiparesis (classic lacunar syndromes)
    • Pure sensory deficit
    • Pure sensory-motor deficit
    • Hemiparesis, homolateral ataxia
    • Dysarthria/clumsy hand
  • Vertebrobasilar Artery Cerebrovascular Accident (CVA)
    • Cranial nerve palsies
    • Crossed sensory deficits
    • Diplopia, dizziness, nausea, vomiting, dysarthria, dysphagia, hiccup
    • Limb and gait ataxia
    • Motor deficit
    • Coma
    • Bilateral signs suggest basilar artery disease
• Multiple Sclerosis (see Multiple Sclerosis)
  • Clinical: xxxx
• Postictal (Todd’s) Paralysis (see Seizures)
  • Physiology
    • Often Related to a Structural Abnormality of the Brain
  • Clinical
    • Focal Motor Deficit Following Generalized or Complex Partial Seizure
    • Can Persist for Hours, But Usually Lasts for 30-60 min
• Spinal Dural Arteriovenous Fistula (AVF) (see Spinal Dural Arteriovenous Fistula)
• Subarachnoid Hemorrhage (SAH) (see Subarachnoid Hemorrhage)
• Subdural Hematoma (SDH) (see Subdural Hematoma)
• Transient Ischemic Attack (TIA) (see Transient Ischemic Attack)
• Traumatic Brain Injury (TBI) (see Traumatic Brain Injury)

Bilateral Weakness

• Brainstem Disease
  • Brainstem Hemorrhage (see Intracerebral Hemorrhage)
  • Brainstem Ischemic Cerebrovascular Accident (CVA) (see Ischemic Cerebrovascular Accident)
    • Clinical
      • Bulbar Deficits
      • Ipsilateral Cranial Nerve and Contralateral Body Weakness
      • Oculomotor Deficits
      • Vertigo (see Vertigo)
      • Visual Field Deficits
• Spinal Cord Disease
  • Acute Spinal Cord Injury (see Acute Spinal Cord Injury)
  • Amyotrophic Lateral Sclerosis (ALS) (see Amyotrophic Lateral Sclerosis)
  • Chronic Inflammatory Demyelinating Polyneuropathy (CIDP) (see Chronic Inflammatory Demyelinating Polyneuropathy)
  • Chronic Spinal Cord Injury (see Chronic Spinal Cord Injury)
  • Spinal Cord Hematoma (Hematomyelia) (see Spinal Cord Hematoma)
  • Spinal Cord Infarction (see Spinal Cord Infarction)
  • Spinal Cord Tumor
  • Spinal Epidural Abscess (see Spinal Epidural Abscess, [[Spinal Epidural Abscess]])
  • Spinal Epidural Hematoma (see Spinal Epidural Hematoma, [[Spinal Epidural Hematoma]])
  • Transverse Myelitis (see Transverse Myelitis, [[Transverse Myelitis]])]
• Peripheral Neuropathy (see Peripheral Neuropathy, [[Peripheral Neuropathy]])
  • Acute Intermittent Porphyria (see Acute Intermittent Porphyria, [[Acute Intermittent Porphyria]])
  • Buckthorn Berry Intoxication (see Buckthorn Berry Intoxication, [[Buckthorn Berry Intoxication]])
  • Diphtheria (see Diphtheria, [[Diphtheria]])
  • Guillain-Barre Syndrome (GBS) (see Guillain-Barre Syndrome, [[Guillain-Barre Syndrome]])
    • Clinical
      • Progressive (Ascending) Symmetric Weakness with Decreased/Absent Deep Tendon Reflexes (see Hyporeflexia, [[Hyporeflexia]])
  • Mojave Rattlesnake Bite (see Rattlesnake Bite, [[Rattlesnake Bite]])
  • Neurotoxic Shellfish Poisoning (see Neurotoxic Shellfish, [[Neurotoxic Shellfish]])
    • Clinical: descending paralysis (in contrast to ascending paralysis seen in GBS and tick paralysis)
  • Palytoxin Poisoning (see Palytoxin, [[Palytoxin]])
  • Paralytic Shellfish Poisoning (see Paralytic Shellfish, [[Paralytic Shellfish]])
    • Clinical: descending paralysis (in contrast to ascending paralysis seen in GBS and tick paralysis)
  • Poisonous Lizard Bite (see Poisonous Lizard Bite, [[Poisonous Lizard Bite]])
  • Rabies (see Rabies, [[Rabies]]): ascending paralysis (may mimic that of Guillian-Barre syndrome)
  • Tick Paralysis (see Tick Paralysis, [[Tick Paralysis]])
    • XXXX
  • Widow Spider Bite (see Widow Spider Bite, [[Widow Spider Bite]])
• Neuromuscular Junction Disease
  • Botulism (see Botulism, [[Botulism]])
    • Clinical
      • xxxx
  • Lambert-Eaton Myasthenic Syndrome (LEMS) (see Lambert-Eaton Myasthenic Syndrome, [[Lambert-Eaton Myasthenic Syndrome]])
  • Myasthenia Gravis (MG) (see Myasthenia Gravis, [[Myasthenia Gravis]])
    • Clinical
      • xxxx
  • Organophosphate/Carbamate Intoxication (see Organophosphates/Carbamates, [[Organophosphates-Carbamates]])
    • Clinical
      • Cholinergic Symptoms
  • Pharmacologic Neuromuscular Junction Antagonists
    • Aminoglycosides (see Aminoglycosides, [[Aminoglycosides]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Fluoroquinolones (see Fluoroquinolones, [[Fluoroquinolones]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Anti-Cholinergics (see xxxx, [[xxxx]]): usually clinically relevant only in the presence of other neuromuscular disease
    • Procainamide (see Procainamide, [[Procainamide]]): usually clinically relevant only in the presence of other NM disease
    • Polymyxin Antibiotics (see Polymyxins, [[Polymyxins]]): usually clinically relevant only in the presence of other neuromuscular disease
      • Colistin (Polymyxin E, Colistimethate Sodium) (see Colistin, [[Colistin]])
      • Polymyxin B (see Polymyxin B, [[Polymyxin B]])
    • Neuromuscular Junction Antagonists (see Neuromuscular Junction Antagonists, [[Neuromuscular Junction Antagonists]])
      • Succinylcholine (see Succinylcholine, [[Succinylcholine]])
      • Aminosteroid Non-Depolarizing Blockers (Pancuronium, Vecuronium, etc)
      • Benzylisoquinolone Non-Depolarizing Blockers (Atracurium, etc)
• Muscle Disease
  • Myopathy (see Myopathy, [[Myopathy]])
    • Alcoholic Myopathy (see Ethanol, [[Ethanol]])
    • Infection
      • Tetanus (see Tetanus, [[Tetanus]])
      • Human Immunodeficiency Virus (HIV) (see Human Immunodeficiency Virus, [[Human Immunodeficiency Virus]])
      • Lyme Disease (see Lyme Disease, [[Lyme Disease]])
      • Coxsackie Virus (see Coxsackie Virus, [[Coxsackie Virus]])
      • Tick Paralysis (see Tick Paralysis, [[Tick Paralysis]]): ascending paralysis (similar to GBS, in contrast to descending paralysis seen in paralytic-neurotoxic shellfish poisoning and botulism)
    • Metabolic
      • Hypoglycemia (see Hypoglycemia, [[Hypoglycemia]])
      • Addison’s Disease (see Adrenal Insufficiency, [[Adrenal Insufficiency]])
      • Cushing Syndrome (see Cushing Syndrome, [[Cushing Syndrome]])
      • Hypokalemic Periodic Paralysis (see Hypokalemic Periodic Paralysis)
      • Hyperkalemic Periodic Paralysis (see Hyperkalemic Periodic Paralysis)
      • Thyrotoxic Periodic Paralysis (see Thyrotoxic Periodic Paralysis)
      • Type 1 Glycogen Storage Disease
    • Muscular Dystrophies
    • Sarcoidosis-Associated Myopathy (see Sarcoidosis)
    • Systemic Lupus Erythematosus (SLE)-Associated Myopathy (see Systemic Lupus Erythematosus)
    • Drug/Toxin
      • Corticosteroids (see Corticosteroids)
      • AZT (see xxxx)
      • Excessive Licorice Ingestion (see Licorice)
    • Other
      • Critical Illness Polymyopathy (see xxxx)
      • Polydermatomyositis (see Polydermatomyositis)

Generalized Weakness

• Acute Coronary Syndrome (ACS) (see Coronary Artery Disease, [[Coronary Artery Disease]])
  • Epidemiology: generalized weakness may be the presentation particularly in elderly patients, diabetics, and/or female patients
• Anemia (see Anemia, [[Anemia]])
  • Epidemiology: generalized weakness is common
• Drugs
  • β-Blockers (see β-Adrenergic Receptor Antagonists, [[β-Adrenergic Receptor Antagonists]])
  • Chemotherapy
  • Diuretics
  • Ethanol (see Ethanol, [[Ethanol]])
  • Isoniazid (INH) (see Isoniazid, [[Isoniazid]])
  • Laxatives
  • Opiates (see Opiates, [[Opiates]])
• Endocrine/Metabolic
  • Adrenal Insufficiency (see Adrenal Insufficiency, [[Adrenal Insufficiency]])
    • Epidemiology: xxx
    • Clinical: xxx
  • Hypercalcemia (see Hypercalcemia, [[Hypercalcemia]])
    • Epidemiology: xxx
    • Clinical: xxx
  • Hypoglycemia (see Hypoglycemia, [[Hypoglycemia]])
    • Epidemiology: xxx
    • Clinical: generalized or focal weakness
  • Hypokalemia (see Hypokalemia, [[Hypokalemia]])
  • Hypothyroidism (see Hypothyroidism, [[Hypothyroidism]])
    • Epidemiology: xxx
    • Clinical: xxx
  • Pheochromocytoma (see Pheochromocytoma, [[Pheochromocytoma]])
    • Epidemiology: may occur in some cases
• Hypovolemia (see Hypovolemic Shock, [[Hypovolemic Shock]])
• Infection
  • Malaria (see Malaria, [[Malaria]])
• Periodic Paralysis Syndrome
  • Hyperkalemic Periodic Paralysis (see Hyperkalemic Periodic Paralysis, [[Hyperkalemic Periodic Paralysis]])
  • Hypokalemic Periodic Paralysis (see Hypokalemic Periodic Paralysis, [[Hypokalemic Periodic Paralysis]])
  • Thyrotoxic Periodic Paralysis (see Thyrotoxic Periodic Paralysis, [[Thyrotoxic Periodic Paralysis]])
• Rheumatologic
  • Polymyalgia Rheumatica (PMR) (see Polymyalgia Rheumatica, [[Polymyalgia Rheumatica]])
  • Rheumatoid Arthritis (RA) (see Rheumatoid Arthritis, [[Rheumatoid Arthritis]])
  • Systemic Lupus Erythematosus (SLE) (see Systemic Lupus Erythematosus, [[Systemic Lupus Erythematosus]])
• Sepsis (see Sepsis, [[Sepsis]])
• Toxin
  • Carboxyhemoglobinemia (see Carboxyhemoglobinemia, [[Carboxyhemoglobinemia]])
    • Clinical
      • XXX

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Diagnosis

Head CT (see Head Computed Tomography, [[Head Computed Tomography]])

• xxx

Brain MRI (see Brain Magnetic Resonance Imaging)

• xxxx

Pulmonary Function Tests (PFT’s) (see Pulmonary Function Tests, [[Pulmonary Function Tests]])

• xxx

Electromyogram (EMG)/Nerve Conduction Velocities (NCV) (see Electromyogram/Nerve Conduction Velocity, [[Electromyogram-Nerve Conduction Velocity]])

• xxxxx

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References

• xxx